diff --git a/lib/Cake/Console/Command/CommandListShell.php b/lib/Cake/Console/Command/CommandListShell.php
index 4bf5b9356..67e0005cb 100644
--- a/lib/Cake/Console/Command/CommandListShell.php
+++ b/lib/Cake/Console/Command/CommandListShell.php
@@ -85,6 +85,7 @@ class CommandListShell extends Shell {
 		$shellList = $this->_appendShells('CORE', $shells, $shellList);
 
 		$appShells = App::objects('Console/Command', null, false);
+		$appShells = array_diff($appShells, $shells);
 		$shellList = $this->_appendShells('app', $appShells, $shellList);
 
 		$plugins = CakePlugin::loaded();
diff --git a/lib/Cake/Console/Command/Task/ExtractTask.php b/lib/Cake/Console/Command/Task/ExtractTask.php
index 50c8c94b5..ab5ceaaf9 100644
--- a/lib/Cake/Console/Command/Task/ExtractTask.php
+++ b/lib/Cake/Console/Command/Task/ExtractTask.php
@@ -353,6 +353,9 @@ class ExtractTask extends Shell {
 		foreach ($models as $model) {
 			App::uses($model, $plugin . 'Model');
 			$reflection = new ReflectionClass($model);
+			if (!$reflection->isSubClassOf('Model')) {
+				continue;
+			}
 			$properties = $reflection->getDefaultProperties();
 			$validate = $properties['validate'];
 			if (empty($validate)) {
diff --git a/lib/Cake/Core/App.php b/lib/Cake/Core/App.php
index dadb8f7bc..c2234deba 100644
--- a/lib/Cake/Core/App.php
+++ b/lib/Cake/Core/App.php
@@ -447,9 +447,6 @@ class App {
 
 			if (empty($path)) {
 				$path = self::path($type, $plugin);
-				if (empty($plugin)) {
-					$path = array_merge($path, App::core($type));
-				}
 			}
 
 			foreach ((array)$path as $dir) {
diff --git a/lib/Cake/Test/Case/Core/AppTest.php b/lib/Cake/Test/Case/Core/AppTest.php
index c878edcf4..0a96e7378 100644
--- a/lib/Cake/Test/Case/Core/AppTest.php
+++ b/lib/Cake/Test/Case/Core/AppTest.php
@@ -303,6 +303,14 @@ class AppTest extends CakeTestCase {
 		$this->assertTrue(in_array('Dispatcher', $result));
 		$this->assertTrue(in_array('Router', $result));
 
+		App::build(array(
+			'Model/Behavior' => App::core('Model/Behavior'),
+			'Controller' => App::core('Controller'),
+			'Controller/Component' => App::core('Controller/Component'),
+			'View' => App::core('View'),
+			'Model' => App::core('Model'),
+			'View/Helper' => App::core('View/Helper'),
+		), App::RESET);
 		$result = App::objects('behavior', null, false);
 		$this->assertTrue(in_array('TreeBehavior', $result));
 		$result = App::objects('Model/Behavior', null, false);